Expansion roof for fluid storage tanks



March 24, 1942. P. s. GRANER 2,277,393

I EXPANSION ROOF FOR FLUID STORAGE TANKS Filed Oct. 5', 1959 4Sheets-Sheet 1 l I v i Q, E a 4 I INVENTORP Phzlzpfifiraver,

ATTORNEY 5 March 24, 1942.

P. S. GRAVER v EXPANSION ROOF FOR FLUID STORAGE TANKS Filed Oct. 5, 19594 Sheets-Sheet 2 INVENT OR.

' ATTORNEYS March 24, 1942. I P. s. GRAVER 2,277,398

EXPANSION ROOFK FOR FLUID STORAGE TANKS Fil ed Oct. 5, 1959 4Sheets-Sheet 3 Lg INVENTOR P/uZgb i Graver,

ATTORNEY 5.

March 24, 1942.

P. S. GRAVER EXPANSION RQOF FOR FLUID STORAGE TANKS- Filed 001;. '5,1959 4 Sheets-Sheei 4 IN VENTOR.

.P/YLZQb 5 Graper;

I E ATTORNgYS Patented Mar. 24, 19 42 Philip S. Graver, Chicago, 111.,assignor to Graver Tank &

aeration of Delaware Application October 5, 1939, Serial No. 298,009

13 Claims.

The invention relates to storagev tanks for storing gases or volatileliquids and has reference more particularly to an improved gas holdertype of roof for said tanks capable of moving in a vertical direction tovary the vapor space within the tank.

The type of storage tank above described is relatively large in diameterand accordingly the surface area of liquid subjected to variableclimatic conditions is substantial. During the heat of the day thevapors produced as a result of evaporation will materially increase thepressure within the tank. However, if these vapors are conserved theycan be reclaimed during the night, owing to the cooler night temperaturewhich condenses the vapors. The production of vapors during the day,followed by subsequent cooling and condensing of the vapors during thenight, is known as breathing and in large tanks, particularly if onlypartly filled, such breathing will be substantial. Also when the oil ispumped into the tanks the agitationincreases the generation of vapors.However, filling of a tank with oil decreases the vapor spaceland herealso the vapor pressure within the tank may become dangerously high.

It is well known that severe evaporation losses will result during thestoring 'of volatile liquids such as gasoline or the like if the vaporsare expelled to the atmosphere in order to relieve the pressure within'the tanks. Thus, as a matter of economy it is necessary to conserve thevapors so that they can be eventually condensed without any loss of thevaluable fractions.

The invention. has for its primary object to provide an improved gasholder type of roof for oil storage tanks which as a result of itsmovement will provide ample vapor space to take care of breathing of thetank under any and all conditions. Another and morespecific object is toprovide a roof of the type described which will have considerablemovement in a vertical direction to vary the vapor space within the tankso that it Mi'g. 00., Inc., Catasauqua, Pa., a corspecial cross-sectiondepending from the roof in combination with flexible guide cables forcontrolling the movement of the roof so .that it will rise and fall in atrue vertical direction.

With these and various'other objects in view,

the invention may consist of certain novel fea-.

a tank and roof being shown in section and with suitably secured as bywelding and by the angle to the atmosphere even under the most severebreathing conditions.

A further object of the invention is to provide a gas holder type ofroof with improved means for maintaining the roof substantiallyhorizontal during vertical movement thereof and which will also preventundesirable rotation of the roof with respect to the tank;

A more specific object of the inventionis to provide improved meansincluding posts oi the roof in deflated position;

Figure 2 is a horizontal sectional view taken substantially along line2-2 of Figure l and showing the arrangement of the flexible cables inpairs;

Figure 3 is a fragmentary sectional view showing in elevation theconstructional features of the depending posts and their associationwith rollers and asheave, the latter having engagement with a flexiblecable;

Figure 4 is afragmentary elevational view, parts being shown in section,of a pair of posts and their associated rollers and sheaves asillustrated in Figure 3; and

Figures 5 and 6 are modifications embodying a fabric seal.

The embodiment of the invention shown in the drawings comprises an opentop tank, Figure 1, having. cylindrical side walls ill, a base lladapted to rest on the earth or other suitable support, and supportingstructure including acenter post l2 having a cap IS on which the centerportion of the roof may rest whenin deflated position. The cylindricalwalls l0 of the tank are reinforced at their upper end by means of aninwardly directed shell girder I4 which is member l5 to the tank wall ashort distance below the. extreme upper end thereof. The shell girderstifiens the upper end of the tank wall and is in turn reinforced by anangle member l6 which extends around the inner periphery of 1 the shellgirder. I p 7 Also secured to the cylindrical tank walls Ill somedistance below the shell girder II are other girders or brackets l8extending inwardly or the tank and suitably supported by means of thetriangular plates IS. The brackets l8 are located ail-spaced intervalsalong the inside periphmanner similar to brackets l3.

The outer circumference of the tank at the upper end is provided with alaunder 23 formed by the cylindrical member 24 and which is spaced fromand concentric with the wall IU of the tank. The launder is completed bythe angle member 25 which forms the base of the launder and thus thebottom of the circumferential trough containing the'oil or other sealingliquid for sealing the roof with respect to the open top tank.

In accordance with the present invention said tank is equipped with amovable roof in the form of a holder bell indicated in its entirety bynumeral 26 and which has telescoping relation with respect to thecylindrical wall It. The bell includes a cambered roof 21 having adepending skirt 28 for location within the launder and also having a'depending rain shed skirt 30 which forms a cover for the launder,protecting the same from the weather. The rain shed skirt is concentricwith the skirt 23 and the same is suitably secured to the outerperiphery of the roof 21 by the angle member 3|.

For guidingand controlling the vertical movements of the holder bell theinvention provides depending posts 32 of special cross section which aresuitably secured as by welding to the cambered roof 21. The posts dependvertically downward passing through openings in the shell girders andrest on the supporting brackets 2| provided therefor. when the dependingposts 32 have contact with their supporting brackets 2! the holderbellis in deflated position and said posts accordingly function assupporting means for the roof in this position, a portion of the weightof the holder bell being transmitted to the side walls III of the tank.The posts 32 are arranged in pairs and which are spaced around theperipheral portion of the roof as best illustrated in Figure 2. Incrosssection said posts simulate an H and as a result of said cross sectioneach post has guiding contact with the rollers and with a sheave, thelatter also having contact with a flexible cable as shown in Figures 3and 4. 7

Referring to said figures, the lower portion of each post has guidingcontact with rollers 33 and 34 suitably journalled by shafts 35 in theside plates 20 extending upwardly on the respective sides of each of thebrackets i 3. Each depending post is additionally guided by meansincluding a roller 38 and an associated sheave 31. each arrangement ofroller-and sheave being suitably joumalled in side members 33 supportedon the shell girder l4. A shaft 39 journals the roller 36 and as shownin Figure 4 said roller is provided with peripheral projections 43adapted to have location within the side flanges'of its respective post32. In a similar manner the sheave 31 is suitably Journalled by shaft 4|and the periphery of said sheave is likewise provided with projections42, which have location within the side channels of the post on the sideopposite the roller 38.

As shown in ,Figure 2, the depending posts are arranged in pairs and.accordingly the associated roller and sheave are likewise arranged inpairs. Each sheave in addition to having contact with I its dependingpost carries a flexible cable which plane. Each cable is secured at oneend to the roof 21, whereas, its other end has securement to the base ofa depending post 32. Thus, the flexible cables as well as the sheaveswith which they engage are located entirely within the tank and areprotected from the elements.

Referring to Figure 1, which shows a pair of flexible cables, it will beseen that each cable for a part of its length includes a rod identifiedby numerals 43 and 44, respectively, having a turnbuckle 45 at one endand connecting with chains which engage the sheaves. At the right handend of rod 43 the chain 46 connecting therewith passes over itsrespective sheave 31 and depends vertically downward within the post 32for securement thereto at the base by means of hook 41. To accommodatethe chains it will be observed by reference to Figure 4 that each sheave31 is provided with a groove 48 located centrally thereof between thespaced projections 42. The rod 43 at its left hand end connects withchain 53 which passes under its respective sheave 31 on this side of thetank extending upwardly for securement to the roof as at 5!. In asimilar manner the rod 44 has chains 52 and 53 secured to the respectiveendsithereof, the former passing under a sheave and being secured to theroof, whereas, the latter passes over a sheave and depends verticallydownward for securement to the lower end of its post 32.

During operation of the movable roof of the present invention it will beunderstood that the launder 23 will contain oil or water as a sealingmedium for the dependingskirt 23. The space within the cylindrical wallIII of the tank may also contain oil if the tank is being used as astorage tank, or the entire space within the same may be used forstoring gas. In both cases when the pressure exceeds the weight of theholder bell and the post structure depending therefrom, the same willtend to rise and it is this movement of the holder hell that iscontrolled by the depending posts 32 and theflexible cables abovedeplane. The deflatedposition of the roof is fixed by the supportingstructure including the central post i2 and by the depending posts 32which rest on brackets 2i. The posts 32 also limit the inflated positionof the roof since the plates 54 will engage brackets l3 when the holderbell has moved upwardly a predetermined amount. The brackets act as astop since the plates 54 are relatively large in size and will not passthrough the openings in the brackets through which the depending postsextend. The movable roof of the invention can be easily adapted to oldtanks and of course may be employed with new tanks. The movement of theroof may vary considerably. depending on the size of the tank to whichthe same is appliedand the nature of the liquid stored therein. In anyevent, the roof may have movement such as will provide ample space totake care of breathing under the most severe conditions. It is of primeimportance that the roof move up and down in a vertical plane and shedskirt 30.

that the roof be prevented from rotating with respect to the open toptank. This is the function of the depending posts 32 and the flexiblecables. By using the posts as connections for the flexible cables it ispossible to make the liquid seal launder much narrower than is possiblein those designs where one end Iof each cable depends verticallydownward within the launder for connection to the lower end of thedepending skirt of the holder bell. K

In the modifications of the invention shown in Figures and 6 the liquidseal for the holder bell is eliminated and a fabric seal substitutedthere.-

for. With this exception the open top tank and holder bell is similar inconstruction to that shown in Figure 1.

Referring to Figure 5, it will be observed that the launder and thedepending skirt of the holder hell have both been eliminated. In thisform of the invention the seal is made between the cylindrical wall IIIof the tank and the depending rain The fabric 60 which extends aroundthe tank is suitably secured along one edge to the .side wall Illthrough the instrumentality of the angle member GI and bolts 62, whichsecure the fabric to said angle member. The angle member is in turnsuitably welded to the wall of the tank. The other edge of the flexiblefabric is secured to the rain shed skirt 30 at the upper end'thereof. Achannel 63 isusedfor this connection since "he bolts 64 extend asexplained with respect to Figure 1 and said flexible cables also havecontact with their. respective sheave 31. It will be understood that theflexible fabric 6|! of Figure 5 and the fabric 68 of Figure 6 extendscircumferentially around the tank and as a result the interior of thetank is sealed from the atmosphere although vertical movement oftheholder bell is possible.

The invention is not to be limited to or by details of construction ofthe particular embodiment thereof illustrated by the drawings, asvarious other forms of the device will of course be apparent to thoseskilled in the art without departing from the spirit of the invention orthe scope of the claims.

What is claimed. is:

1. In a storage container for gas or liquid, in combination, an open toptank arranged to provide a body of sealing liquid, a holder bellproviding a roof for said tank and movable with respect thereto to varythe vapor space within the tank, said holder bell having a dependingperipheral skirt located within the sealing liquid so as to confinevapors within the tank, a plurality of postsfixed to the roof at spacedpoints circ'umferentially of the same and depending within said tank,rollers supported from side wall of i the tank and having contactwitheach post, re-

through the skirt and are accessible from the outside of the bellholder. To prevent collapse of the fabric when vacuum conditions existwithin the tank the weight 65 is suspended from the roof of the tank bythe chain 66 and said weight is located substantially centrally of thespace occupied by the fabric. The length of the chain 66 isapproximately one-half that of the fabric so that the weight just barelycontacts the fabric when the roof is in deflated position, as shown infull lines in Figure 5. When inflated the weight also has contact withthe fabric to retain control of the same. e

In Figure 6 a length of fabric extends across the space formed by theside wall ll! of the tank and the depending rain shed skirt. The fabric68 along one edge is suitably secured to the angle member 69 welded tothe side wall ID of the tank a short distance below the extreme top ofsaid I tank. The other edge of the fabric is secured nel '|0 isemployed.- With the roof 2! in deflated position it will be observedthat the fabric 68 is somewhat slack. The full movement of the roof willdetermine the length of the flexible fabric forming the seal thereforand by properly locating the angle 69 on the tank sidewall and thechannel 10 on the rain shed skirt "it is possible to have some slack inthe fabric in deflated position and also in inflated position. In anyevent, it is not intended to place any tension on the fabric since themovement of the roof is limited by the depending posts 32 and the stopsprovided therefor-f In both forms of the invention, as shown in Figures5. and 6, the depending posts rest on brackets 2| when the roof is indeflated position and during vertical movement of said roof thedepending posts are guided as'a result of contact with the rollers 33and 34, and with the roller 36 in combination with the sheave 31. Theflexible cables are connected to the roof and'to the lower end of thedepending posts in' the same manner spectively, for guiding the sameduring said ver-- tical movement, flexible cables secured at theirrespective ends to substa'ntilly diametrically spaced points on theholder ell and movable with respect to thetank for guiding andcontrolling the holder bell during its up and down movement, and sheavesadapted to engage the cables at intermediate points, each sheave havingone of said rollers associated therewith and also having contact withits respective depending post. i

2. In a storage container for gas or liquid, in combination, an open toptank arranged to provide a body of sealing liquid, a holder bellproviding a roof for said tank and movable with respect thereto to. varythe vapor space within the tank, said holder bell having a dependingperipheral skirt located within the sealing liquid so as to confinevapors within the tank, a plurality of posts fixed to the roof atcircumferentially spaced points and depending within said tank, spacedbrackets supported from the cylindrical wall of the tank and havingassociation with each depending post, one of said spaced bracketsjournalling rollers having guiding contact with its respective dependingpost and the other of said spaced brackets providing a support on whichits respective post may rest when the roof is in deflated position.

3. In a storage container for gas or liquid, in combination, an open toptank arranged to provide a body of sealing'liquid, a holder bellproviding a roof for said tank and movable with respect thereto to varythe vapor space within the tank, said holder bell having a dependingperipheral skirt located within the sealing liquid so as to confinevapors within the tank, a plurality of posts fixed to the roof atcircumferentially spaced points and depending within said having rollingcontact with each depending post,

respectively, including a roller and a sheave spaced from each othersothat a post passes therebetween, and flexible-cables for maintainingthe holder bell substantially .horizontal durtank including a holderbell havingits depending vertical movement thereof, said flexible cableshaving contact with said sheaves at points intermediate thereof.

4. In a storage container for gas or liquid, in combination, an open toptank arranged to provide a body of sealing liquid, a holder bellproviding a roof for said tank and movable with respect thereto to varythe vapor space within the tank, said holder bell having a dependingperipheral skirt located within the sealing liquid so as'to confinevapors within the tank, a plurality of posts fixed to the roof atcircumferentially spaced points and depending within said tank, a shellgirder fixed to the cylindrical wall of the tank near its upper end andextending inwardly, means supported by said shell girder and havingrolling contact with each depending post, respectively, including aroller and a sheave spaced from each other so that a post passestherebetween, and flexible cables for maintaining the holder bellsubstantially horizontal during movement thereof, each cable at pointsintermediate its ends having contact with said sheaves and each cable atone end being secured to the roof and at its other end having connectionwith a depending post, near the lower end thereof.

5. In a storage container for gas or liquid, in combination, an open toptank arranged to provide a body of sealing liquid, a holder bellproviding a roof for said tank and movable with respect thereto to varythe vapor space within thetank, said holder bell having a dependingperipheral skirt located within the sealing liquid so as to confinevapors within the tank, a plurality of posts fixed to the roof atcircumferentially spaced points and depending within said tank, a shellgirder fixed to the cylindrical wall of the tank near its upper end andextending inwardly, means supported by said shell girder and havingrolling contact with each depending post, respectively, including aroller and a sheave spaced from each other so that a post passestherebetween, flexible cables extending substantially diametrically andbeing, located within said tank, each cable at one end passing under asheave and being secured to the roof and at its opposite end passingover a sheave and depending vertically downward for securement to adepending post near the lower end thereof.

6. In a storage container for petroleum prod ucts and the like, incombination, an open top tank having a launder at the upper end thereofcontaining sealing liquid, a movable roof for the tank including aholder bell having its depending member located within the sealingliquid so as to confine vapors Within the tank, a plurality of postssecured to the roof at circumfer'entially spaced points anddependingwithin said tank, flexible cables for maintaining the holder bellsubstantially horizontal during vertical movement thereof, each cable atits respective ends having securement to the holder bell atsubstantially diametrically spaced points, sheaves for engaging thecables at points intermediate their connection with the holder bell,each of said sheaves also having contact with a depending post, and aroller associated with each sheave and adapted to have contact with theopposite I side of the depending pOst whereby a post is located betweenand has guiding contact with a sheave and a roller.

7. In a storage container for petroleum products and the like, incombination, an open top tank having a launder at the upper end thereofcontaining sealing liquid, a movable roof for the from each otherwhereby the post passes therebetween, the periphery of each sheave androller having projections extending within the side flanges of itsrespective depending post, whereby each post is properly oriented andthe holder bell is prevented from rotating during vertical movement, andflexible cables located within the tank and extending substantiallydiametrically thereof, one end of each cable passing under one of saidsheaves and extending upwardly for securement to the roof, the other endof each cable passing over a sheave and depending vertically downwardfor connection to a post near the lower end thereof.

8. In a storage container for gas or liquid, in combination, an open toptank, a holder bell providing'a root for said tank and movable withrespect thereto to vary the vapor space within the tank, means providinga seal between the tank and holder bell so as to confine vapors withinthe tank, a plurality of posts fixed to the roof at circumi'erentiallyspaced points and depending within said tank, spaced brackets supportedfrom the cylindrical wall of the tank and having association with eachdepending post, one of said spaced brackets Journalling rollers havingguiding contact with its respective depending post and the other of saidspaced the tank, means providing a seal between the tank and holder bellso as to confine vapors with in the tank, a plurality of posts fixed tothe root at clrcumferentially spaced points and depending within saidtank, a shell girder fixed to the cylindrical wall of the tank near itsupper end and extending inwardly, means supported by said shell girderand having rolling contact with each depending post, respectively,including a roller and a sheave spaced from each other so that a postpasses therebetween, and flexible cables for maintaining the holder bellsubstantially horizontal during vertical movement thereof, said flexiblecables having contact with said sheaves at points intermediate thelength of said cables.

10. In a storage container for gas or liquid, in

combination, an open .top tank, a holder bell providing a roof for saidtank and movable with respect thereto to vary the vapor space within thetank, means providing a seal between the tank and holder bell so as toconfine vapors "with each depending post, respectively, including aroller and a sheave spaced from each other so that a post passestherebetween, fiexiblecables for maintaining the holder bellsubstantially horizontal during movement thereof, each cable. aplurality of posts fixed to the holder bell at at points intermediateits ends having contact with said sheaves and each cable at one endbeing secured to the roof and at its other end having connection with adepending post near the lower end thereof.

11. In a storage container for gas or liquid, in combination, an opentop tank, a holder bell providing a roof for said tank and adapted'tohave vertical movement with respect thereto to vary the vapor spacewithin the tank, means providing a seal between the tank and holder bellso as to confine said vapors within the tank, a plurality of postsdepending from the underside of said holder bell within the tank, aplurality of shell girders fixed to the cylindrical wall of the tank inspaced relation vertically thereof and being directed inwardly of thetank, said shell girders having aligned openings through which thedepending posts extend, sets of rollers supported by one girder andhaving rolling contact with each depending post respectively for guidingthe same in its up and down movement, a plurality of sheaves supportedby the other girder, and flexible cables for maintaining the holderbellsubstantially horizontal during movement thereof, said cables beinglocated within the tank and having contact with the sheaves at pointsintermediate their ends, each cable at one end being secured to the roofand at its other end having connection with a depending post near thelower end thereof.

12. In a storage container for gas or liquid, in combination, an opentop tank, a holder bell providing a roof for said tank and adapted tohave vertical movement with respect thereto to vary the vapor spacewithin the tank, means providing a. seal between the tank and holderbell so as to confine said vapors within the tank, a

plurality of shell girders fixed to the cylindrical wall of the tank inspaced relation vertically thereof and being directed inwardly of thetank,

circumferentially spaced points and depending within the tank throughaligned openings formed in said girders, a plurality of sets of rollerssupported by one girder and having rolling contactwith its respectivedepending post for guiding the same in its up and, down movement, aplurality of sheaves supported by the other girder adjacent-each of thedepending posts, and flexible cables extending substantiallydiametrically within the tank, each cable at one end passing under asheave and being secured to the roof and at its other end passing over asheave and depending vertically downward for securement to a dependingpost near the lower end thereof.

13. In a storage container for gas or liquid in combination, an open toptank, a holder bell providing a roof for said tank and adapted to havevertical movement with respect thereto to vary the vapor space withinthe tank, means providing a seal between the tank and holder bell so asto confine said vapors within the tank, a plurality of posts dependingfrom the underside of said holder bell within the tank, a shell girderfixed to the cylindrical wall of the tank and being directed inwardly ofthe tank, said shell girder having openings through which the dependingposts extend, a plurality of sets of rollers supported by said girderand having rolling contact with each depending post respectively forguiding the same in its up and down movement, a plurality of sheavessupported from the cylindrical wall of the tank adjacent each of thedepending posts, and flexible cables extending substantiallydiametrically within the tank, each cable at one end passing under asheave and being secured to the roof, and at its opposite end passingover a sheave and depending vertically downward for securement' to adepending post near the lower end thereof.

' PHILIP S. GRAVE-R.

